The aims of this study are to prepare and characterize human antibodies to human immunodeficiency virus type I (HIV-1), respiratory syncytial virus (RSV), cytomegalovirus (CMV), varicella zoster virus (VZV), measles virus and cryptosporidium parvum. The success of the approach is dependent upon the availability of tissue containing antibody- producing cells from appropriate donors identified by our colleagues in the Division of Infectious Diseases.